Nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation, preparation method therefor and use thereof

Abstract

The present invention provides a nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation, a preparation method therefor and a use thereof. According to the nitrogen-containing polymer, an aromatic primary amine diazonium salt and a secondary diamine are used as polymer monomers, and a monofunctional secondary amine modifier is added to undergo a two-phase interfacial polycondensation reaction. The nitrogen-containing polymer modified by the monofunctional secondary amine modifier has high sensitivity to ultraviolet light, and chain segments in the polymer each consist of small molecular fragments, so that ultraviolet cleaning ablation under low laser energy density can be achieved, cleaning and recycling of the matrix are facilitated, and the nitrogen-containing polymer thus has environmentally-friendly and energy-saving properties. The number-average molecular weight of the nitrogen-containing polymer is 100,000 or less, and the maximum thermal weight loss rate temperature can reach 275℃ or above; a film prepared from the nitrogen-containing polymer has a wide range of ultraviolet absorption in the wavelength range of 265-375 nm, the absorbance of the film having a thickness of 200 nm can reach 2.0 or more, and cleaning ablation without solid residues can be achieved using low-energy ultraviolet laser having a laser energy density of 25 mJ / cm2.

Description

A nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation, and its preparation method and application Technical Field

[0001] The invention relates to a nitrogen-containing polymer capable of realizing low-energy ultraviolet cleaning ablation, a preparation method and application thereof, and belongs to the technical field of polymer materials. Background Art

[0002] Currently, there are many reports on the research of laser ablation polymers. Various photosensitive polymers have been designed and prepared for laser ablation processing, from aspects such as ablation photodecomposition, surface treatment, thin film deposition, and material transfer. These designed photosensitive polymers will undergo significant changes in structure or properties under laser irradiation, thereby achieving specific functionality. However, one of the most common problems with infrared laser ablation photosensitive polymers is the high heat load of the infrared laser on the photosensitive polymer material. When processing composite systems containing substances such as biomaterials, organic dyes, and electroluminescent polymers, the existence of this high heat load is fatal, causing unnecessary thermal defects and heat-induced side effects to the composite system, and even causing the system to fail. Therefore, for certain composite systems containing heat-sensitive substances, the use of infrared laser ablation photosensitive polymers and production processes will be greatly limited.

[0003] While UV laser-ablative photopolymers avoid the high heat loads associated with infrared laser ablation, the high energy of UV lasers can damage composite systems containing photosensitive materials, such as single molecules, living cells, and semiconductor polymers. The photochemical reactions generated by these destructive, high-energy UV lasers also limit the practical application of UV laser-ablative photopolymers and their production processes.

[0004] In addition, various reports have synthesized laser-ablative polymers based on arylazo groups, including polyalkylarylazosulfides, diazosulfonate polymers, triazene-containing copolyesters, triazene-containing polyurethanes, and triazene-containing polyacrylates. Among these laser-ablative polymers, triazene polymers can be effectively decomposed and ablated under UV laser irradiation, exhibiting excellent UV ablation properties and making them promising candidates for photosensitive polymers for UV laser ablation. However, conventional triazene polymers still have significant limitations in practical applications, such as specific absorption range, laser energy density, shelf life, and chemical compatibility. Therefore, to avoid the application limitations imposed by the high thermal load of infrared lasers and the high energy of UV lasers, while simultaneously meeting the requirements of practical applications such as the transfer of biological cell systems and single molecules, high-resolution full-color printing, the release of prefabricated components in microelectromechanical system assembly, and the structural transfer of semiconducting polymers in organic light-emitting diodes, it is essential to prepare a new type of photosensitive polymer that can achieve low-energy UV ablation.

[0005] Summary of the Invention

[0006] To address the aforementioned problems of the prior art, the present invention provides a nitrogen-containing polymer capable of low-energy UV cleaning and ablation, and a method for preparing the same. The resulting nitrogen-containing polymer exhibits significant UV sensitivity and broad UV absorption. Under low laser energy density, it undergoes effective photochemical decomposition to generate volatile small molecule fragments, achieving clean ablation without contaminating the system and facilitating substrate cleaning and recycling. Furthermore, the nitrogen-containing polymer exhibits excellent chemical compatibility and a long shelf life.

[0007] To achieve the above objectives, the present invention provides a nitrogen-containing polymer that can achieve low-energy ultraviolet cleaning and ablation. The nitrogen-containing polymer is prepared using a diazonium salt of an aromatic primary amine and a secondary diamine as monomers, and a monofunctional secondary amine modifier is added during the polymerization reaction; wherein the nitrogen-containing polymer has a number average molecular weight of less than 100,000 and a maximum thermal weight loss rate temperature of above 275°C.

[0008] The present invention also provides a preparation method of a nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation, comprising the following steps: 1) adding concentrated acid and aromatic primary amine to water under stirring; fully stirring and dispersing the mixture at -10°C to 5°C, and then dropwise adding a sodium nitrite aqueous solution; after the addition is completed, continuing stirring for 25 minutes to 60 minutes to obtain a diazonium salt aqueous solution; 2) adding a secondary diamine and a monofunctional secondary amine modifier to a hydrochloric acid aqueous solution under stirring; fully stirring and dissolving the mixture to obtain a secondary amine aqueous solution; 3) adding crushed ice and an alkane solvent to a reaction vessel; and then adding the sodium nitrite aqueous solution to the reaction vessel. The diazonium salt aqueous solution and the secondary amine aqueous solution are sequentially added to the container and stirred mechanically; then, the buffer solution is added dropwise at -10°C to 5°C and stirred; then, the pH adjusting solution is added and stirred, and the reaction is carried out at -10°C to 5°C for 20min to 40min; then, the temperature is raised to -5°C to 10°C and the stirring reaction is continued for 20min to 40min; then, the temperature is raised to 0°C to 15°C and the stirring reaction is continued for 20min to 40min; then, the temperature is raised to 10°C to 25°C and the stirring reaction is continued for 40min to 80min; after the reaction is completed, , leaving it at room temperature overnight to obtain a mixed solution containing the modified nitrogen-containing polymer; 4) filtering the mixed solution containing the modified nitrogen-containing polymer to obtain a filter cake; adding an alkane cleaning agent, an ether cleaning agent, a secondary alcohol cleaning agent, a primary alcohol cleaning agent and water to the filter cake in sequence, ultrasonically cleaning with stirring, and then filtering to obtain a mixture containing the modified nitrogen-containing polymer; 5) drying the mixture containing the modified nitrogen-containing polymer at normal pressure and 50°C to 100°C for 8h to 24h; and then drying at -0.1Mpa and 50°C to 100°C. Continue drying under the conditions for 12 hours to 48 hours. After drying, a crude modified nitrogen-containing polymer is obtained; 6) dissolving the crude modified nitrogen-containing polymer in a good solvent, then centrifuging to remove insoluble matter in the solution, and taking the supernatant; adding the supernatant to the poor solvent under stirring, and continuing to stir for 0.5 hours to 2.5 hours after the addition is completed, and then filtering to obtain a filter cake; adding water to the filter cake, ultrasonically and stirring to clean it, then filtering it, and drying it to constant weight to obtain the nitrogen-containing polymer that can achieve low-energy UV cleaning ablation.

[0009] As an improvement, in the step 1), the amounts used are: 50 mL to 100 mL of water, 50 mL to 100 mL of concentrated acid, 100 mmol to 200 mmol of aromatic primary amine, and 100 mL to 400 mL of sodium nitrite aqueous solution; in the step 2), the amounts used are: 100 mL to 200 mL of hydrochloric acid aqueous solution, 100 mmol to 200 mmol of secondary diamine, and 10 mmol to 50 mmol of monofunctional secondary amine modifier; in the step 3), the amounts used are: 100 g to 200 g of crushed ice, 75 mL to 150 mL of alkane solvent, 50 mL to 150 mL of buffer, and 100 mL to 200 mL of pH adjusting solution.

[0010] As an improvement, in step 1), the concentrated acid is selected from one or a mixture of concentrated hydrochloric acid with a mass fraction of 36-38wt% and concentrated sulfuric acid with a mass fraction of 95-98wt%; the aromatic primary amine is selected from one or a mixture of 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, and 4,4'-diaminobenzophenone; and the concentration of the sodium nitrite aqueous solution is 1 mol / L to 2 mol / L.

[0011] As an improvement, in step 2), the hydrochloric acid aqueous solution is prepared by adding 50 mL to 200 mL of 36 wt% to 38 wt% concentrated hydrochloric acid to water and diluting the volume to 500 mL; the secondary diamine is selected from one or a mixture of N,N'-dimethylethylenediamine, N,N'-dimethyl-1,3-propylenediamine, N,N'-dimethyl-1,4-butanediamine, N,N'-dimethyl-1,5-pentanediamine, N,N'-dimethyl-1,6-hexanediamine, and N,N'-dimethyl-1,2-cyclohexanediamine; and the monofunctional secondary amine modifier is selected from one or a mixture of N-methyl-n-propylamine, N-ethyl-n-propylamine, di-n-propylamine, N-methyl-n-butylamine, N-ethyl-n-butylamine, N-methyl-n-pentylamine, N-ethyl-n-pentylamine, N-methylcyclohexylamine, and N-ethylcyclohexylamine.

[0012] As an improvement, in step 3), the alkane solvent is selected from one or a mixture of cyclopentane, n-hexane, cyclohexane, and n-heptane; the buffer solution is selected from one or a mixture of dipotassium hydrogen phosphate aqueous solution, disodium hydrogen phosphate aqueous solution, potassium phosphate aqueous solution, and sodium phosphate aqueous solution; and the pH adjusting solution is selected from one or a mixture of potassium hydroxide aqueous solution and sodium hydroxide aqueous solution.

[0013] As an improvement, in step 4), the alkane cleaning agent is selected from one or a mixture of cyclopentane, n-hexane, cyclohexane, and n-heptane; the ether cleaning agent is selected from one or a mixture of methyl tert-butyl ether, ethyl tert-butyl ether, and isopropyl ether; the secondary alcohol cleaning agent is selected from one or a mixture of isopropanol and sec-butanol; and the primary alcohol cleaning agent is selected from one or a mixture of methanol, ethanol, and propanol.

[0014] As an improvement, in step 6), the good solvent is selected from one or a mixture of N,N-dimethylformamide, N,N-dimethylacetamide, and tetrahydrofuran; and the poor solvent is selected from one or a mixture of methanol, ethanol, and water.

[0015] The present invention also provides the use of the nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning and ablation in the field of nitrogen-containing polymer films.

[0016] As an improvement, the maximum ultraviolet absorbance wavelength of the nitrogen-containing polymer film in the wavelength range of 265-375nm is 325-335nm; the ultraviolet absorbance of the nitrogen-containing polymer film with a thickness of 200nm reaches above 2.0, and the laser energy density of the low-energy ultraviolet laser for cleaning and ablation is 80mJ / cm 2 the following.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention utilizes a primary aromatic amine diazonium salt and a secondary diamine as polymer monomers, causing them to undergo a two-phase interfacial polycondensation reaction under strong mechanical stirring. Furthermore, a monofunctional secondary amine modifier is added during the polymerization reaction. The molecular weight of the nitrogen-containing polymer modified with the monofunctional secondary amine modifier is effectively reduced, and the prepared polymer also possesses characteristic functional groups of aryldialkyltriazenes, exhibiting high sensitivity to ultraviolet light and enabling ultraviolet ablation at low laser energy densities. Therefore, modification of the nitrogen-containing polymer with the monofunctional secondary amine modifier effectively improves the polymer's original solubility and ultraviolet ablation performance. Furthermore, because the chain segments in the polymer are all composed of triazene groups, short aliphatic carbon chains, or benzene rings, the presence of these segments allows the polymer to decompose into volatile small molecules after ultraviolet ablation, leaving no solid residue. This achieves clean ablation, does not contaminate the system, and facilitates substrate cleaning and recycling.

[0019] The prepared nitrogen-containing polymer capable of achieving low-energy UV cleaning and ablation has a number-average molecular weight below 100,000 and a maximum thermal weight loss rate temperature above 275°C. The prepared modified nitrogen-containing polymer is a uniform and fine solid powder with good solubility. After the nitrogen-containing polymer is prepared into a solution in a certain proportion, it can be prepared into a thin film by spin coating and baking. The laser energy density is 80mJ / cm 2 The following low-energy UV laser ablation of nitrogen-containing polymer films can achieve clean ablation without residue. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below through examples. However, it should be understood that the specific embodiments described herein are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention pertains. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0022] Example 1

[0023] A method for preparing a nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation comprises the following steps:

[0024] 1) Measure 85 mL of water and, while stirring, add 45 mL of 37 wt% concentrated hydrochloric acid, 5 mL of 98 wt% concentrated sulfuric acid, 65 mmol of 4,4'-diaminodiphenyl ether, and 35 mmol of 4,4'-diaminobenzophenone; after thorough stirring and dispersing at 5°C, add 100 mL of a 2 mol / L sodium nitrite aqueous solution dropwise; after complete addition, continue stirring for 40 minutes to obtain a diazonium salt aqueous solution;

[0025] 2) 50 mL of 37 wt% concentrated hydrochloric acid was measured and dissolved in water, and the volume was adjusted to 500 mL to obtain a hydrochloric acid aqueous solution; 200 mL of the hydrochloric acid aqueous solution was measured and, while stirring, 80 mmol of N,N'-dimethylethylenediamine, 20 mmol of N,N'-dimethyl-1,2-cyclohexanediamine, 6 mmol of N-methyl-n-propylamine, and 4 mmol of N-ethylcyclohexylamine were added; after thorough stirring and dissolution, a secondary amine aqueous solution was obtained;

[0026] 3) Weigh 100 g of crushed ice, 60 mL of cyclohexane, and 40 mL of n-heptane, and add them to a flask; then, add the diazonium salt aqueous solution prepared in step 1) and the secondary amine aqueous solution prepared in step 2) to the flask in sequence, and stir vigorously; then, add 150 mL of dipotassium hydrogen phosphate aqueous solution dropwise at 5° C. and stir; then, add 25 mL of sodium hydroxide aqueous solution and 75 mL of potassium hydroxide aqueous solution, stir, and react at 5° C. for 30 minutes; then, heat to 10° C. and continue stirring and reacting for 20 minutes; then, heat to 15° C. and continue stirring and reacting for 30 minutes; then, heat to 25° C. and continue stirring and reacting for 40 minutes; after the reaction, stand at room temperature overnight to obtain a mixed solution containing the modified nitrogen-containing polymer;

[0027] 4) filtering the mixed solution containing the modified nitrogen-containing polymer prepared in step 3) to obtain a filter cake; sequentially adding cyclohexane, a mixture of ethyl tert-butyl ether and isopropyl ether, sec-butanol, a mixture of ethanol and propanol, and water to the filter cake, ultrasonically cleaning with stirring, and then filtering to obtain a mixture containing the modified nitrogen-containing polymer;

[0028] 5) drying the mixture containing the modified nitrogen-containing polymer prepared in step 4) at 100° C. for 8 h; then drying at -0.1 MPa and 80° C. for 24 h to obtain a crude modified nitrogen-containing polymer;

[0029] 6) taking the crude modified nitrogen-containing polymer prepared in step 5), dissolving it in a mixture of N,N-dimethylformamide, N,N-dimethylacetamide and tetrahydrofuran, then centrifuging to remove insoluble matter in the solution, and taking the supernatant; adding the supernatant to methanol under stirring, continuing to stir for 1.5 hours after the addition is complete, and then filtering to obtain a filter cake; adding water to the filter cake, ultrasonically cleaning and stirring, then filtering, and drying to constant weight to obtain a nitrogen-containing polymer capable of low-energy UV cleaning and ablation;

[0030] The prepared nitrogen-containing polymer capable of achieving low-energy UV cleaning and ablation has a number-average molecular weight of approximately 82,500 and is a uniform, fine orange-yellow solid powder with a long shelf life and a maximum thermal weight loss rate of 279.6°C. It has good solubility and can be prepared into a thin film by spin coating. The prepared nitrogen-containing polymer film has a thickness of 254 nm and exhibits broad UV absorption in the range of 265 to 375 nm, with a maximum UV absorbance wavelength of 330 nm and an absorbance of 2.48. The laser energy density used is 25 mJ / cm 2 Clean ablation can be achieved using low-energy ultraviolet lasers.

[0031] Example 2

[0032] A method for preparing a nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation comprises the following steps:

[0033] 1) Measure 100 mL of water and, while stirring, add 65 mL of 38 wt% concentrated hydrochloric acid, 15 mL of 95 wt% concentrated sulfuric acid, and 150 mmol of 4,4'-diaminodiphenyl ether; after thorough stirring and uniform dispersion at -3°C, add 215 mL of a 1.4 mol / L aqueous sodium nitrite solution dropwise; after complete addition, continue stirring for 25 minutes to obtain a diazonium salt aqueous solution;

[0034] 2) 110 mL of 38 wt% concentrated hydrochloric acid was measured and dissolved in water, and the volume was adjusted to 500 mL to obtain a hydrochloric acid aqueous solution; 135 mL of the hydrochloric acid aqueous solution was measured and, while stirring, 75 mmol of N,N'-dimethyl-1,4-butanediamine, 40 mmol of N,N'-dimethyl-1,5-pentanediamine, 25 mmol of N,N'-dimethyl-1,6-hexanediamine, and 35 mmol of di-n-propylamine were added; after thorough stirring and dissolution, a secondary amine aqueous solution was obtained;

[0035] 3) Weigh 155 g of crushed ice, 50 mL of cyclopentane, and 100 mL of n-hexane, and add them to a flask; then, add the diazonium salt aqueous solution prepared in step 1) and the secondary amine aqueous solution prepared in step 2) to the flask in sequence, and stir vigorously; then, at -10°C, add 75 mL of a dipotassium hydrogen phosphate aqueous solution, 30 mL of a disodium hydrogen phosphate aqueous solution, and 20 mL of a sodium phosphate aqueous solution dropwise, and stir; then, add 145 mL of a potassium hydroxide aqueous solution, stir, and react at -10°C for 40 minutes; then, heat to -5°C, continue stirring and react for 40 minutes; then, heat to 0°C, continue stirring and react for 40 minutes; then, heat to 10°C, continue stirring and react for 80 minutes; after the reaction, stand at room temperature overnight to obtain a mixed solution containing a modified nitrogen-containing polymer;

[0036] 4) filtering the mixed solution containing the modified nitrogen-containing polymer prepared in step 3) to obtain a filter cake; sequentially adding a mixture of cyclopentane and n-hexane, methyl tert-butyl ether, isopropanol, ethanol, and water to the filter cake, ultrasonically cleaning with stirring, and then filtering to obtain a mixture containing the modified nitrogen-containing polymer;

[0037] 5) drying the mixture containing the modified nitrogen-containing polymer prepared in step 4) at 50° C. for 24 h; then drying at -0.1 MPa and 50° C. for 48 h to obtain a crude modified nitrogen-containing polymer;

[0038] 6) taking the crude modified nitrogen-containing polymer prepared in step 5), dissolving it in N,N-dimethylformamide, then centrifuging to remove insoluble matter in the solution, and taking the supernatant; adding the supernatant to a solution of methanol and water under stirring, continuing to stir for 0.5 hours after the addition is complete, and then filtering to obtain a filter cake; adding water to the filter cake, ultrasonically cleaning and stirring, then filtering, and drying to constant weight to obtain a nitrogen-containing polymer capable of low-energy UV cleaning and ablation;

[0039] The prepared nitrogen-containing polymer capable of achieving low-energy UV cleaning and ablation has a number-average molecular weight of approximately 70,500 and is a uniform, fine orange solid powder with a long shelf life and a maximum thermal weight loss rate of 281.5°C. It has good solubility and can be prepared into a thin film by spin coating. The prepared nitrogen-containing polymer film has a thickness of 199 nm and exhibits broad UV absorption in the range of 265 to 375 nm, with a maximum UV absorbance wavelength of 331 nm and an absorbance of 2.06. The laser energy density used is 50 mJ / cm 2 Clean ablation can be achieved using low-energy ultraviolet lasers.

[0040] Example 3

[0041] A method for preparing a nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation comprises the following steps:

[0042] 1) Measure 50 mL of water and, while stirring, add 100 mL of 36 wt% concentrated hydrochloric acid, 90 mmol of 4,4'-diaminodiphenylmethane, 60 mmol of 4,4'-diaminodiphenyl ether, and 50 mmol of 4,4'-diaminodiphenyl sulfone; after thorough stirring and dispersing at -10°C, add 400 mL of a 1 mol / L sodium nitrite aqueous solution dropwise; after complete addition, continue stirring for 60 minutes to obtain a diazonium salt aqueous solution;

[0043] 2) Measure 200 mL of 36 wt% concentrated hydrochloric acid, dissolve it in water, and dilute to 500 mL to obtain a hydrochloric acid aqueous solution; measure 100 mL of the hydrochloric acid aqueous solution, and add 200 mmol of N,N'-dimethyl-1,3-propylenediamine, 20 mmol of N-ethyl-n-propylamine, 15 mmol of N-methyl-n-butylamine, 10 mmol of N-ethyl-n-pentylamine, and 5 mmol of N-methylcyclohexylamine under stirring; stir thoroughly to dissolve to obtain a secondary amine aqueous solution;

[0044] 3) Weigh 200 g of crushed ice and 75 mL of n-hexane, and add them to a flask; then, add the diazonium salt aqueous solution prepared in step 1) and the secondary amine aqueous solution prepared in step 2) to the flask in sequence, and stir vigorously; then, add 25 mL of sodium phosphate aqueous solution and 25 mL of potassium phosphate aqueous solution dropwise at -5°C, and stir; then, add 100 mL of sodium hydroxide aqueous solution and 100 mL of potassium hydroxide aqueous solution, stir, and react at -5°C for 20 minutes; then, heat to 0°C, continue stirring and react for 30 minutes; then, heat to 10.5°C, continue stirring and react for 20 minutes; then, heat to 15°C, continue stirring and react for 60 minutes; after the reaction, stand at room temperature overnight to obtain a mixed solution containing the modified nitrogen-containing polymer;

[0045] 4) filtering the mixed solution containing the modified nitrogen-containing polymer prepared in step 3) to obtain a filter cake; sequentially adding n-hexane, a mixture of cyclohexane and n-heptane, a mixture of methyl tert-butyl ether and ethyl tert-butyl ether, a mixture of isopropanol and sec-butanol, a mixture of methanol and propanol, and water to the filter cake, ultrasonically cleaning with stirring, and then filtering to obtain a mixture containing the modified nitrogen-containing polymer;

[0046] 5) drying the mixture containing the modified nitrogen-containing polymer prepared in step 4) at 75° C. for 12 h; then drying at -0.1 MPa and 100° C. for another 12 h, to obtain a crude modified nitrogen-containing polymer;

[0047] 6) taking the crude modified nitrogen-containing polymer prepared in step 5), dissolving it in a mixture of N,N-dimethylformamide and tetrahydrofuran, then centrifuging to remove insoluble matter in the solution, and collecting the supernatant; adding the supernatant to a solution of ethanol and water under stirring, continuing to stir for 2.5 hours after the addition is complete, and then filtering to obtain a filter cake; adding water to the filter cake, ultrasonically cleaning and stirring, then filtering, and drying to constant weight to obtain a nitrogen-containing polymer capable of low-energy UV cleaning and ablation;

[0048] The prepared nitrogen-containing polymer capable of achieving low-energy UV cleaning and ablation has a number-average molecular weight of approximately 64,800 and is a uniform, fine orange-red solid powder with a long shelf life and a maximum thermal weight loss rate of 276.5°C. It has good solubility and can be prepared into a thin film by spin coating. The prepared nitrogen-containing polymer film has a thickness of 206 nm and exhibits broad UV absorption in the range of 265 to 375 nm, with a maximum UV absorbance wavelength of 330.5 nm and an absorbance of 2.09. The laser energy density used is 80 mJ / cm 2 Clean ablation can be achieved using low-energy ultraviolet lasers.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation, characterized in that: The nitrogen-containing polymer is prepared by using aromatic primary amine diazonium salt and secondary diamine as monomers, and adding a monofunctional secondary amine modifier during the polymerization reaction; The number average molecular weight of the nitrogen-containing polymer is below 100,000, and the maximum thermal weight loss rate temperature is above 275°C.

2. The method for preparing a nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation according to claim 1, characterized in that: The following steps are involved: 1) Add concentrated acid and aromatic primary amine to water under stirring; After being fully stirred and dispersed at -10°C to 5°C, the sodium nitrite aqueous solution is added dropwise; after the addition is completed, stirring is continued for 25min to 60min to obtain a diazonium salt aqueous solution; 2) adding a secondary diamine and a monofunctional secondary amine modifier to the hydrochloric acid aqueous solution under stirring; stirring and dissolving the mixture sufficiently to obtain a secondary amine aqueous solution; 3) Add crushed ice and alkane solvent to the reaction container; then add the diazonium salt aqueous solution and secondary amine aqueous solution to the reaction container in sequence, and stir vigorously mechanically; then add buffer dropwise at -10°C to 5°C, stir; then add pH adjusting liquid, stir, and react at -10°C to 5°C for 20min to 40min; then heat to -5°C to 10°C, continue stirring to react for 20min to 40min; then heat to 0°C to 15°C, continue stirring to react for 20min to 40min; then heat to 10°C to 25°C, continue stirring to react for 40min to 80min; after the reaction is completed, leave it at room temperature overnight to obtain a mixed solution containing a modified nitrogen-containing polymer; 4) filtering the mixed solution containing the modified nitrogen-containing polymer to obtain a filter cake; sequentially adding an alkane cleaning agent, an ether cleaning agent, a secondary alcohol cleaning agent, a primary alcohol cleaning agent and water to the filter cake, ultrasonically cleaning and stirring, and then filtering to obtain a mixture containing the modified nitrogen-containing polymer; 5) drying the mixture containing the modified nitrogen-containing polymer at normal pressure and 50° C. to 100° C. for 8 to 24 hours; and then continuing to dry at -0.1 MPa and 50° C. to 100° C. for 12 to 48 hours. After drying, a crude modified nitrogen-containing polymer is obtained; 6) dissolving the crude modified nitrogen-containing polymer in a good solvent, then centrifuging to remove insoluble matter in the solution, and taking the supernatant; adding the supernatant to a poor solvent under stirring, continuing to stir for 0.5h to 2.5h after the addition is completed, and then filtering to obtain a filter cake; adding water to the filter cake, ultrasonically and stirring to clean it, then filtering it, and drying it to constant weight to obtain the nitrogen-containing polymer that can achieve low-energy ultraviolet cleaning ablation.

3. The method for preparing a nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation as claimed in claim 2, characterized in that: In the step 1), the amounts used are: 50 mL to 100 mL of water, 50 mL to 100 mL of concentrated acid, 100 mmol to 200 mmol of aromatic primary amine, and 100 mL to 400 mL of sodium nitrite aqueous solution; In the step 2), the amounts used are: 100 mL to 200 mL of aqueous hydrochloric acid, 100 mmol to 200 mmol of secondary diamine, and 10 mmol to 50 mmol of monofunctional secondary amine modifier; In the step 3), the amounts used are: 100 g to 200 g of crushed ice, 75 mL to 150 mL of alkane solvent, 50 mL to 150 mL of buffer solution, and 100 mL to 200 mL of pH adjusting solution.

4. The method for preparing a nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation as claimed in claim 2, characterized in that: In the step 1), the concentrated acid is selected from one of concentrated hydrochloric acid with a mass fraction of 36-38wt% and concentrated sulfuric acid with a mass fraction of 95-98wt%, or a mixture of the two; The aromatic primary amine is selected from one or a mixture of 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, and 4,4'-diaminobenzophenone; The concentration of the sodium nitrite aqueous solution is 1 mol / L to 2 mol / L.

5. The method for preparing a nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation as claimed in claim 2, characterized in that: In the step 2), the aqueous hydrochloric acid solution is prepared by adding 50 mL to 200 mL of 36 wt% to 38 wt% concentrated hydrochloric acid to water and fixing the volume to 500 mL; The secondary diamine is selected from one or a mixture of N,N'-dimethylethylenediamine, N,N'-dimethyl-1,3-propylenediamine, N,N'-dimethyl-1,4-butanediamine, N,N'-dimethyl-1,5-pentanediamine, N,N'-dimethyl-1,6-hexanediamine, and N,N'-dimethyl-1,2-cyclohexanediamine; The monofunctional secondary amine modifier is selected from one of N-methyl-n-propylamine, N-ethyl-n-propylamine, di-n-propylamine, N-methyl-n-butylamine, N-ethyl-n-butylamine, N-methyl-n-pentylamine, N-ethyl-n-pentylamine, N-methylcyclohexylamine, and N-ethylcyclohexylamine, or a mixture of several thereof.

6. The method for preparing a nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation as claimed in claim 2, characterized in that: In the step 3), the alkane solvent is selected from one or a mixture of cyclopentane, n-hexane, cyclohexane, and n-heptane; The buffer solution is selected from one or a mixture of dipotassium hydrogen phosphate aqueous solution, disodium hydrogen phosphate aqueous solution, potassium phosphate aqueous solution, and sodium phosphate aqueous solution; The pH adjusting liquid is selected from potassium hydroxide aqueous solution, sodium hydroxide aqueous solution or a mixture of the two.

7. The method for preparing a nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation as claimed in claim 2, characterized in that: In the step 4), the alkane cleaning agent is selected from one or a mixture of cyclopentane, n-hexane, cyclohexane, and n-heptane; The ether cleaning agent is selected from one or a mixture of methyl tert-butyl ether, ethyl tert-butyl ether, isopropyl ether; The secondary alcohol cleaning agent is selected from one of isopropanol and sec-butyl alcohol or a mixture of the two; The primary alcohol cleaning agent is selected from methanol, ethanol, propanol or a mixture of several thereof.

8. The method for preparing a nitrogen-containing polymer capable of achieving low-energy ultraviolet cleaning ablation as claimed in claim 2, characterized in that: In step 6), the good solvent is selected from one or a mixture of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran; The poor solvent is selected from methanol, ethanol, water or a mixture thereof.

9. Use of the nitrogen-containing polymer capable of realizing low-energy ultraviolet cleaning ablation as claimed in claim 1 in the field of nitrogen-containing polymer films.

10. The use according to claim 9, characterized in that The maximum ultraviolet absorbance wavelength of the nitrogen-containing polymer film in the wavelength range of 265-375nm is 325-335nm; The ultraviolet absorbance of the nitrogen-containing polymer film with a thickness of 200 nm is above 2.0, and the laser energy density of the low-energy ultraviolet laser for cleaning and ablation is 80 mJ / cm 2 the following.